camera_aravis

Actively maintained repository for the ROS1 camara_aravis driver. It is open source under the LGPL (like Aravis itself).

The Aravis library is a glib/gobject based library for video acquisition using Genicam cameras. It currently implements the gigabit ethernet and USB3 protocols used by industrial cameras.

The camera_aravis driver has long history of multiple forks and now abandoned GitHub repositories. This repository is based on https://github.com/florisvb/camera_aravis.git, which in turn was forked from a deleted github repo (https://github.com/CaeruleusAqua/camera_aravis), which was itself forked from https://github.com/ssafarik/camera_aravis.

Tested with Aravis version 0.6.X. Since Ubuntu 20.04 the library can be installed from the official Ubuntu package repository. Install with:

sudo apt install libaravis-dev

The basic command to run camera_aravis:

$ rosrun camera_aravis cam_aravis

To run it in a given namespace:

$ ROS_NAMESPACE=cam1 rosrun camera_aravis cam_aravis

Continuous Integration

Service	Noetic	Master
GitHub
ROS Build Farm		N/A

Configuration

This ROS node publishes messages image_raw and camera_info for a specified camera. It supports a variety of camera features via the ROS reconfigure_gui, including the following: * ExposureAuto (string: Off, Once, Continuous) * GainAuto (string: Off, Once, Continuous) * ExposureTimeAbs (float) * Gain (float) * AcquisitionMode (string: Continuous, SingleFrame, MultiFrame) * AcquisitionFrameRate (float) * TriggerMode (string: Off, On) * TriggerSource (string: Any, Software, Line0, Line1, Line2) * softwaretriggerrate (float) * frame_id (string) * FocusPos (integer) * mtu (integer)

Note that the above are also the ROS parameter names of their respective feature. You may set initial values for the camera by setting ROS parameters in the camera's namespace.

In addition to the above features, this driver now supports (almost) every feature of every camera, you just have to know how the feature is specified; each GenICam-based camera contains an XML file onboard, and by viewing this file you can determine which ROS parameters to set for camera_aravis to write to the camera. You can use arv-tool-0.2 to see the feature list and the XML file (e.g. "arv-tool-0.2 --name=Basler-21285878 features")

Note that for this special feature access, the ROS parameter type must match the feature type. For example, a Basler ac640 has a boolean feature called "GammaEnable", an integer feature called "BlackLevelRaw", and a string enum feature called "PixelFormat" that takes values (Mono8, Mono12, Mono12Packed, YUV422Packed, etc). The ROS params that you set for these must be, respectively, a bool, an integer and a string. Also note that boolean features must be specified as ROS params false/true, not as integer 0/1.

$ rosparam set /camera_aravis/GammaEnable false
$ rosparam set /camera_aravis/BlackLevelRaw 5
$ rosparam set /camera_aravis/PixelFormat Mono12
$ rosrun camera_aravis cam_aravis

camera_aravis supports multiple cameras, each of which may be specified on the command-line, or via parameter. Runs one camera per node.

To specify which camera to open, via the command-line:

$ rosrun camera_aravis cam_aravis _guid:=Basler-21237813

To specify which camera to open, via a parameter:

$ rosparam set /camera_aravis/guid Basler-21237813
$ rosrun camera_aravis cam_aravis

It supports the dynamic_reconfigure protocol, and once the node is running, you may adjust its parameters by running the following and then manipulating the GUI:

$ rosrun dynamic_reconfigure reconfigure_gui

There is an additional nice feature related to timestamps that unifies ROS time with camera time. We want a stable timestamp on the images that the camera delivers, giving a nice smooth time delta from frame to frame. If we were to use the ROS clock on the PC, by the time we get the image packets from the camera a variable amount of time has passed on the PC's clock due to variable network and system delays. The camera's onboard clock is stable but it doesn't match with the ROS clock on the PC, and furthermore since it comes from a different piece of hardware, the two clock's rates are slightly different.

The solution is to start with a base of ROS time, and to accumulate the dt's from the camera clock. To accomodate the difference in clock rates, a PID controller gently pulls the result toward ROS time.

Known Issues

Slow read of white balance and black level values

From PR#22: The white balance and black level values of some cameras (e.g. Basler acA2440-20gc & JAI FS-3200D-10GE ) can be read more efficiently by reading from the exact memory locations of the camera instead of using the Selector features.

However, since we are not sure on how stable these optimizations based on exact memory locations are in terms of firmware updates and how well they generalize to other camera models, we have refrained from merging the pull request into the main repository.

For more information and details on the implementation, please look into the changes and the comments inside the pull request.

Changelog for package camera_aravis

4.0.4 (2022-12-23)

• Update package maintainer
• Refactor node params (#21)
  • Refactor node params
  • Rename extended_camera_info_ -> pub_ext_camera_info_
  • Move stream parameters to the top of onInit()
• fix: only reset PTP clock when in \"Faulty\" or \"Disabled\" state (#23)
• Update industrial_ci default branch to main
• Contributors: Dominik Kleiser, Peter Mortimer, Ruf, Boitumelo

4.0.3 (2022-07-08)

• Refactor image conversion (#20)
• Use plain file names for includes (#17)
• Add verbose flag for feature detection (default = false) (#19)
• Assume num_streams_ = 1 if DeviceStreamChannelCount and GevStreamChannelCount unavailable (#18)
• Add Line0 to Line5 to TriggerSource Enum
• Fix: nodelet namespace
• Fix: onInit deadlock
• Contributors: Dominik Kleiser, Boitumelo Ruf, Thomas Emter, Peter Mortimer, tas, Geoff McIver

4.0.2 (2022-05-04)

• Add optional ExtendedCameraInfo message to publish additional camera acquisition parameters
• Fix: Set reasonable height and width when not given in the CameraInfo
• Contributors: Peter Mortimer

4.0.1 (2022-03-25)

• Add ROS getter/setter services for camera features
• Add support for multistream encoding conversion
• Fix: Pass on the correct encoding for the additional streams of multisource cameras
• Fix: Continuously check the spawning_ flag
• Fix: Check spawning_ flag only once during spawnStream
• Contributors: Peter Mortimer, Thomas Emter, Dominik Kleiser

4.0.0 (2021-10-27)

• Major refactoring
• Add support for ROS Noetic and aravis-0.6
• Fix several bugs (see git history)
• Add new features:
  • Support for multisource cameras
  • Zero-copy transport with ROS nodelets
  • Camera time synchronization
  • Example launch files
• Update package author and maintainer
• Contributors: Dominik Klein, Floris van Breugel, Ga